EXPRESSION OF PERIPHERIN IN SOLID TRANSPLANTS OF FETAL SPINAL-CORD AND DORSAL-ROOT GANGLIA GRAFTED TO THE INJURED CERVICAL SPINAL-CORD OF ADULT-RATS

The expression of the neuronal type III intermediate filament protein peripherin was studied in E14 spinal cord fragments and E15 dorsal roo t ganglia 1-30 weeks after their transplantation to the injured cervic al spinal cord of the adult rat. In the dorsal root ganglion transplan ts, the surviving neurons generally appeared as a rather healthy looki ng population of small strongly immunoreactive cells which are very si milar to the small dorsal root ganglion neurons of adult control rats. In the spinal cord transplants, there were only a few peripherin-immu noreactive neurons, morphologically close to the motoneurons or to the preganglionic sympathetic neurons of adult rats. In both types of tra nsplants, peripherin expression of the immunoreactive neurons was appa rently correlated with the previously established ability of these tra nsplanted neurons for extensive axonal growth into a co-grafted periph eral nerve.